GM needs to send their electrical engineers back to school when it comes to the 1999 Pontiac Montana. The wiring for all of the exterior lights in undersized and they turn black under the insulation the entire length of the wire. Then, under the carper where the driver and passenger sit, they crimped together sometimes up to 5 or 6 wires and then put black duct tape around them. How is that sealed from the elements? The snow or rain that is on your shoes soaks into the carpet, around the duct tape, and into the crimp causing it to corrode and the wires fall apart. My van had the back taillights lighting up like a blinking Christmas tree. The power windows wouldn't work. The power door locks wouldn't work. Why all at once? Because there are 20 crimps covered in duct tape under the carpet that corroded and fell apart. Why are they under your feet to begin with? Why duct tape? My wires were so corroded they fell apart when I picked them up. I had to cut off a foot of wire on each end and then the wire was still dark from being undersized. I did not have enough wire left to put it back together. So I had to replace it all. I went down to the local Menards and bought spools of 16 gauge stranded copper wire. I didn't know it is supposed to be shiny when you peel the insulation off of it. Anyways, I replaced the wiring from the terminal block under the dash all the way to the taillights and front turn signals. The taillights both have 5 wires, so you can imagine how much wire it took to replace it all. I also arranged the new wire in a way that all of the splices are all under the trim panel that covers the drivers side rear wheel well so they are not under your feet getting wet. They are also soldered, heatshrinked, and siliconed to provide moisture protection. This was at 40,000 miles and guess what? I have 170,000 miles on it now and have never had another issue with it. Imagine that! I have never seen anything as bad as this. I took pictures but they did not turn out well. It was too dark to see the green ooze that was eating my wires alive.